Decoding Audiogram Results: What Each Line and Symbol Means
An audiogram is the visual record of a hearing test, plotting the softest sounds a person can detect across frequencies measured in hertz (Hz). For anyone who has been handed a copy of their hearing test, those lines, Xs, Os and brackets can feel like a foreign language. Decoding an audiogram matters because it directly informs diagnosis, management and recommendations such as hearing aids or medical evaluation. This article walks through the basic components of an audiogram, the meaning of common symbols and lines, how clinicians distinguish types of hearing loss, and practical questions to ask your audiologist. The goal is to make audiogram interpretation accessible without replacing a trained professional’s assessment.
How an audiogram is constructed and what each axis means
An audiogram is a two-dimensional chart: the horizontal axis shows frequency (pitch) from low to high, usually 125 to 8000 Hz, and the vertical axis shows hearing level in decibels hearing level (dB HL), where higher numbers represent greater hearing attenuation. Pure tone audiometry measures thresholds for air conduction and often for bone conduction. Air conduction tests the entire hearing pathway—outer, middle and inner ear—while bone conduction bypasses the outer and middle ear by vibrating the skull. Understanding the axes is the first step in audiogram interpretation: a shift downward on the graph indicates poorer thresholds at those frequencies, and patterns across frequencies help classify the configuration of hearing loss, which is important for clinical decisions about treatment and counseling.
Common symbols and lines on an audiogram and what they represent
Symbols on an audiogram communicate which ear was tested, whether the measure is air or bone conduction, and whether masking was used. The standard convention is to plot the right ear’s air conduction thresholds with a red O and the left ear’s air conduction with a blue X. Bone conduction results are usually shown with arrows or angle brackets: for left bone conduction. Masked thresholds—used when sound can cross from one ear to the other—are often indicated with brackets ([ and ]) or other annotations. An arrow pointing down at the end of a test frequency typically means “no response” at the test limits. Below is a concise table summarizing the most frequently encountered symbols on audiograms.
| Symbol | Typical Meaning | Used For |
|---|---|---|
| O | Right ear air conduction threshold | Pure tone air conduction |
| X | Left ear air conduction threshold | Pure tone air conduction |
| < | Right ear bone conduction threshold (unmasked) | Bone conduction testing |
| > | Left ear bone conduction threshold (unmasked) | Bone conduction testing |
| [ ] | Masked bone conduction thresholds | Used when crossover is possible |
| ↓ or no mark | No response at maximum test level | Indicates profound threshold or test limit |
Decibel ranges and common configuration patterns in audiograms
Decibel values on the vertical axis correspond to degrees of hearing loss. Clinically, thresholds from 0 to about 20 dB HL are considered within normal limits, mild hearing loss is typically 21–40 dB, moderate 41–55 dB, moderately severe 56–70 dB, severe 71–90 dB and profound over 90 dB. Equally important than degree is the configuration across frequencies: a flat audiogram suggests similar hearing sensitivity across pitches; a sloping audiogram—worse in the high frequencies—is common with age-related and noise-induced loss; a rising configuration is worse in low frequencies; a “cookie-bite” pattern can indicate genetic or inner-ear issues; and a sharp notch around 3–6 kHz is often associated with noise-induced hearing loss. Recognizing these patterns helps clinicians infer likely causes and appropriate interventions such as hearing protection or amplification strategies.
Air-bone gaps and what they reveal about conductive versus sensorineural loss
One of the most clinically useful aspects of audiogram interpretation is comparing air conduction and bone conduction thresholds. If air conduction thresholds are worse than bone conduction thresholds by a meaningful margin (commonly an air–bone gap of 10 dB or more), that suggests a conductive component—something limiting sound transmission through the outer or middle ear, such as earwax, fluid, or ossicular problems. If both air and bone conduction thresholds are elevated with no significant air–bone gap, that pattern indicates sensorineural hearing loss arising from the inner ear or auditory nerve. Mixed loss shows elements of both. This distinction matters because conductive problems may be medically or surgically treatable, whereas sensorineural loss is typically managed through hearing aids, cochlear implant evaluation, or rehabilitative services.
Speech testing, masking notes, and practical questions to bring to your audiologist
Beyond pure tones, an audiogram report usually includes speech measures such as the speech recognition threshold (SRT) and word recognition or speech discrimination scores. These tests show how well a person understands speech at comfortable listening levels and can influence recommendations about amplification or auditory training. Masking notations indicate that the tester controlled for crossover so that thresholds reflect the test ear alone. When reviewing results with an audiologist, ask clear questions: What type and degree of hearing loss do I have? Is there an air–bone gap suggesting a medical issue? Am I a candidate for hearing aids or other devices? What communication strategies or follow-up tests do you recommend? Understanding these clinical implications—alongside the audiogram symbols—helps patients make informed decisions about treatment, hearing aid candidacy and workplace or safety considerations.
Putting the audiogram in context and next steps after your test
An audiogram is a precise clinical tool but it is one piece of a larger diagnostic picture that includes case history, otoscopic exam, tympanometry and speech testing. Interpreting the lines and symbols gives you insight into where the problem lies and the likely next steps, but it doesn’t replace professional guidance. If your audiogram shows a conductive pattern, referral to ENT (otolaryngology) may be appropriate; if sensorineural loss is present, discussion of hearing aid candidacy, assistive listening devices and rehabilitation is typical. Keep a copy of your audiogram for comparisons over time and ask your clinician to annotate test dates and key values so you can track changes. Regular monitoring, workplace protections and prompt evaluation of sudden changes are practical ways to protect hearing health.
This information is intended for educational purposes and does not replace personalized medical evaluation. If you have concerns about hearing changes or the results of a hearing test, consult a licensed audiologist or ear, nose and throat specialist for diagnosis and treatment options tailored to your situation.
This text was generated using a large language model, and select text has been reviewed and moderated for purposes such as readability.
